Coincidentally I have been thinking along these lines myself lately. Gazing into the mirror, I realized that a lot of people of Scottish ancestry have very thick, dark, coarse, bushy eyebrows, as do many North Africans, Portuguese, and Spaniards. I suspect that at least a portion of Scottish DNA is linked to all of those others; remember, there was an ice-age refugium in western Iberia and adjacent North Africa.
p.s. I know a man in DC who is half Scottish and half Berber. I bet he’d have a lot to say about this.